Thermal energy exchanger for a heating, ventilating, and air conditioning system

ABSTRACT

A thermal energy exchanger for a heating, ventilating, and air conditioning system is disclosed, the thermal energy exchanger includes a phase change material disposed therein, whereby the phase change material is at least one of encapsulated by a thermally conductive material and impregnated with a thermally conductive material.

FIELD OF THE INVENTION

The invention relates to a climate control system for a vehicle and moreparticularly to a thermal energy exchanger for a heating, ventilating,and air conditioning system.

BACKGROUND OF THE INVENTION

A vehicle typically includes a climate control system which maintains atemperature within a passenger compartment of the vehicle at acomfortable level by providing heating, cooling, and ventilation.Comfort is maintained in the passenger compartment by an integratedmechanism referred to in the art as a heating, ventilating and airconditioning (HVAC) system. The HVAC system conditions air flowingtherethrough and distributes the conditioned air throughout thepassenger compartment.

Typically, a compressor of a refrigeration system provides a flow of afluid having a desired temperature to an evaporator disposed in the HVACsystem to condition the air. The compressor is generally driven by afuel-powered engine of the vehicle. However, in recent years, vehicleshaving improved fuel economy over the fuel-powered engine and othervehicles are quickly becoming more popular as a cost of traditional fuelincreases. The improved fuel economy is due to known technologies suchas regenerative braking, electric motor assist, and engine-offoperation. Although the technologies improve fuel economy, accessoriespowered by the fuel-powered engine no longer operate when thefuel-powered engine is not in operation. One major accessory that doesnot operate is the compressor of the refrigeration system. Therefore,without the use of the compressor, the evaporator disposed in the HVACsystem does not condition the air flowing therethrough and thetemperature of the passenger compartment increases to a point above adesired temperature.

Accordingly, vehicle manufacturers have used a thermal energy exchangerdisposed in the HVAC system to condition the air flowing therethroughwhen the fuel-powered engine is not in operation. One such thermalenergy exchanger, also referred to as a cold accumulator, is describedin U.S. Pat. No. 6,854,513 entitled VEHICLE AIR CONDITIONING SYSTEM WITHCOLD ACCUMULATOR, hereby incorporated herein by reference in itsentirety. The cold accumulator includes a phase change material, alsoreferred to as a cold accumulating material, disposed therein. The coldaccumulating material absorbs heat from the air when the fuel-poweredengine is not in operation. The cold accumulating material is thenrecharged by the conditioned air flowing from the cooling heat exchangerwhen the fuel-powered engine is in operation.

In U.S. Pat. No. 6,691,527 entitled AIR-CONDITIONER FOR A MOTOR VEHICLE,hereby incorporated herein by reference in its entirety, a thermalenergy exchanger is disclosed having a phase change material disposedtherein. The phase change material of the thermal energy exchangerconditions a flow of air through the HVAC system when the fuel-poweredengine of the vehicle is not in operation. The phase change material ischarged by a flow of a fluid from the refrigeration system therethrough.

While the prior art HVAC systems perform adequately, it is desirable toproduce a thermal energy exchanger having a phase change materialdisposed therein for an HVAC system, wherein an effectiveness andefficiency thereof are maximized.

SUMMARY OF THE INVENTION

In concordance and agreement with the present invention, a thermalenergy exchanger having a phase change material disposed therein for anHVAC system, wherein an effectiveness and efficiency thereof aremaximized, has surprisingly been discovered.

In one embodiment, the thermal energy exchanger for a heating,ventilating, and air conditioning system comprises a main housing havinga hollow interior; a plurality of tubes disposed in the hollow interiorof the housing; and a phase change material disposed in the tubes,wherein the phase change material is at least one of encapsulated with athermally conductive material and impregnated with a thermallyconductive material.

In another embodiment, the thermal energy exchanger for a heating,ventilating, and air conditioning system comprises a hollow main housingincluding a first inlet and a first outlet, wherein the first inlet andthe first outlet are in fluid communication with a source of cooledfluid, the housing further including a second inlet and a second outlet,wherein the second inlet and the second outlet are in fluidcommunication with a heat exchanger disposed in a control module of aheating, ventilating, and air conditioning system, and wherein each ofthe inlets and the outlets perform as a diffuser; a plurality of tubesdisposed in the housing forming open areas therebetween, wherein atleast one of the tubes is adapted to receive one of a fluid from thesource of cooled fluid and a fluid from the heat exchanger therethrough;and a phase change material disposed in the open areas of the housing.

In another embodiment, the thermal energy exchanger for a heating,ventilating, and air conditioning system comprises a main housing havinga hollow interior; a fluid disposed in the housing, the fluid adapted tocirculate through a conduit to a heat exchanger disposed in an HVACmodule of a heating, ventilating, and air conditioning system; and aphase change material disposed in the fluid, wherein the phase changematerial is at least one of encapsulated with a thermally conductivematerial and impregnated with a thermally conductive material.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as other objects and advantages of the invention,will become readily apparent to those skilled in the art from readingthe following detailed description of various embodiments of theinvention when considered in the light of the accompanying drawings inwhich:

FIG. 1 is a schematic flow diagram of an HVAC system including afragmentary sectional view of an HVAC module having a thermal energyexchanger disposed therein according to an embodiment of the invention;

FIG. 2 is a fragmentary cross-sectional view of the thermal energyexchanger illustrated in FIG. 1, wherein the thermal energy exchangerincludes a phase change material impregnated with a thermally conductivematerial;

FIG. 3 is a schematic flow diagram of the HVAC system illustrated inFIG. 1, wherein the thermal energy exchanger is in fluid communicationwith a source of cooled fluid;

FIG. 4 is a fragmentary cross-sectional view of the thermal energyexchanger illustrated in FIG. 3, wherein the thermal energy exchangerincludes an encapsulated phase change material;

FIG. 5 is a fragmentary cross-sectional view of the thermal energyexchanger illustrated in FIG. 3, wherein the thermal energy exchangerincludes an encapsulated phase change material impregnated with athermally conductive material;

FIG. 6 is a schematic flow diagram of an HVAC system including across-sectional view of a thermal energy exchanger having a phase changematerial disposed therein according to another embodiment of theinvention;

FIG. 7 is an enlarged sectional view of the phase change materialdisposed in the thermal energy exchanger illustrated in FIG. 6 withincircle 7, wherein the phase change material is encapsulated;

FIG. 8 is an enlarged sectional view of the phase change materialdisposed in the thermal energy exchanger illustrated in FIG. 6 withincircle 8, wherein the phase change material having a thermallyconductive material disposed therein is encapsulated;

FIG. 9 is a schematic flow diagram of an HVAC system including across-sectional view of a thermal energy exchanger having a phase changematerial disposed therein according to another embodiment of theinvention;

FIG. 10 a schematic flow diagram of the HVAC system illustrated in FIG.9, wherein the thermal energy exchanger includes interleaved tubes;

FIG. 11 a schematic flow diagram of an HVAC system including across-sectional view of a thermal energy exchanger having a phase changematerial disposed therein according to another embodiment of theinvention;

FIG. 12 is an enlarged sectional view of the phase change materialdisposed in the thermal energy exchanger illustrated in FIG. 11 withincircle 12, wherein the phase change material is encapsulated; and

FIG. 13 is an enlarged sectional view of the phase change materialdisposed in the thermal energy exchanger illustrated in FIG. 11 withincircle 13, wherein the phase change material having a thermallyconductive material disposed therein is encapsulated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description and appended drawings describe andillustrate various exemplary embodiments of the invention. Thedescription and drawings serve to enable one skilled in the art to makeand use the invention, and are not intended to limit the scope of theinvention in any manner.

FIGS. 1 and 3 show a heating, ventilating, and air conditioning (HVAC)system 10 according to an embodiment of the invention. The HVAC system10 typically provides heating, ventilation, and air conditioning for apassenger compartment of a vehicle (not shown) The HVAC system 10includes a control module 12 to control at least a temperature of thepassenger compartment.

The module 12 illustrated includes a hollow main housing 14 with an airflow conduit 15 formed therein. The housing 14 includes an inlet section16, a mixing and conditioning section 18, and an outlet and distributionsection (not shown). In the embodiment shown, an air inlet 22 is formedin the inlet section 16. The air inlet 22 is in fluid communication witha supply of air (not shown). The supply of air can be provided fromoutside of the vehicle, recirculated from the passenger compartment ofthe vehicle, or a mixture of the two, for example. The inlet section 16is adapted to receive a blower wheel (not shown) therein to cause air toflow through the air inlet 22. A filter (not shown) can be providedupstream or downstream of the inlet section 16 if desired.

The mixing and conditioning section 18 of the housing 14 is adapted toreceive an evaporator core 24, a thermal energy exchanger 26, and aheater core 28 therein. In the embodiment shown, the thermal energyexchanger 26 and the heater core 28 are disposed downstream of a blenddoor 29. The blend door 29 is adapted to selectively permit a flow ofair through the thermal energy exchanger 26 and the heater core 28 whenthe HVAC system 10 is not operating in a pull-down mode. A filter (notshown) can also be provided upstream of the evaporator core 24, ifdesired. The evaporator core 24 is in fluid communication with a sourceof cooled fluid 30 such as a refrigeration system, for example, througha conduit 36. The source of cooled fluid 30 includes a fluid 37, shownin FIGS. 4 and 5, circulating therein. The fluid 37 absorbs thermalenergy and conditions the air flowing through the HVAC module 12.

As illustrated in FIGS. 2, 4, and 5, the thermal energy exchanger 26 isa louvered-fin heat exchanger. It is understood that the thermal energyexchanger 26 can be any conventional thermal energy exchanger asdesired. The thermal energy exchanger 26 is adapted to absorb thermalenergy and cool the air flowing therethrough when a fuel-powered engineof the vehicle is not in operation. As shown, the thermal energyexchanger 26 includes a plurality of tubes 46 with louvered fins 48formed thereon. Each of the fins 48 abuts an outer surface of the tubes46 for enhancing thermal energy transfer of the thermal energy exchanger26. The fins 48 include a plurality of crests 50 formed thereon. Thecrests 50 are formed substantially parallel to each other and at asubstantially 90 degree angle to the tubes 46. It is understood that thecrests 50 can be formed at any angle to the tubes 46 if desired. Each ofthe crests 50 define an air space 52 extending between the tubes 46 andthe fins 48.

The tubes 46 include a phase change material 56 disposed therein. Thephase change material 56 is any material that melts and solidifies atcertain temperatures and is capable of storing and releasing thermalenergy such as a paraffin wax, an alcohol, water, and any combinationthereof, for example. As illustrated in FIGS. 2 and 5, the phase changematerial 56 can be impregnated with a thermally conductive material 58to further enhance the transfer of thermal energy. It is understood thatthe thermally conductive material 58 can be any conventional materialsuch as a graphite powder, for example. The phase change material 56 isadapted to absorb thermal energy from the air flowing through thethermal energy exchanger 26 when the fuel-powered engine is not inoperation. Accordingly, when the fuel-powered engine of the vehicle isin operation, the phase change material 56 is adapted to release thermalenergy into conditioned air from the evaporator 24 flowing therethrough.

As illustrated in FIG. 3, the thermal energy exchanger 26 can also be influid communication with the source of cooled fluid 30 through a conduit38. A valve 39 can be disposed in the conduit 38 to militate against aflow of the fluid 37 therethrough. The thermal energy exchanger 26 isadapted to absorb thermal energy and cool the air flowing therethroughwhen a fuel-powered engine of the vehicle is not in operation. Thethermal energy exchanger 26 is adapted to receive the fluid 37 from thesource of cooled fluid 30 therethrough. As shown in FIGS. 4 and 5, thephase change material 56 can be encapsulated in a thermally conductivecasing 60 a, or coated with a thermally conductive coating 60 b. Thecasing 60 a and the coating 60 b can be produced from any conventionalmaterial such as a polyethylene, for example. In the embodiment shown,the casing 60 a and the coating 60 b permit the phase change material 56to be disposed in the fluid 37 circulating through the tubes 46 of thethermal energy exchanger 26. The encapsulated phase change material 56is adapted to absorb thermal energy from the air flowing through thethermal energy exchanger 26 when the fuel-powered engine is not inoperation, and release thermal energy into the fluid 37 when thefuel-powered engine is in operation.

As illustrated in FIG. 5, the tubes 46 of the thermal energy exchanger26 can further include a plurality of internal fins 66 formed on aninner surface thereof, and a plurality of screens 68 disposed therein.The internal fins 66 are adapted to further enhance the transfer ofthermal energy of the thermal energy exchanger 26. The screens 68 aredisposed in an inlet 70 and an outlet 72 of each of the tubes 46 andextend across an inner diameter thereof. The screens 68 are adapted topermit the flow of the fluid 37 therethrough while militating againstthe flow of the encapsulated phase change material 56 from the thermalenergy exchanger 26. As shown, the encapsulated phase change material 56can include the thermally conductive material 58 disposed therein.

The heater core 28 and a source of heated fluid 74 are fluidly connectedby a conduit 76. The source of heated fluid 74 can be any conventionalsource of heated fluid such as the fuel-powered engine of the vehicle,for example, and the heated fluid can be any conventional fluid such asan engine coolant, for example. A valve 75 can be disposed in theconduit 76 to selectively militate against a flow of heated fluidtherethrough. The heater core 28 is adapted to release thermal energyand heat the air flowing therethrough when the fuel-powered engine ofthe vehicle is in operation.

In operation, the HVAC system 10 conditions air by heating or coolingthe air, and providing the conditioned air to the passenger compartmentof the vehicle. Air flows through the housing 14 of the module 12. Airfrom the supply of air is received in the inlet section 16 of thehousing 14 in the air inlet 22.

When the fuel-powered engine of the vehicle is in operation, the fluid37 from the source of cooled fluid 30 circulates through the conduit 36.Accordingly, the fluid 37 circulates through the evaporator core 24, asshown in FIG. 1. The air from the inlet section 16 flows into theevaporator core 24 where the air is cooled to a desired temperature by atransfer of thermal energy from the air to the fluid 37 from the sourceof cooled fluid 30. The conditioned air stream then exits the evaporatorcore 24. When the HVAC system 10 is not operating in the pull-down mode,the air from the evaporator core 24 is selectively permitted by theblend door 29 to flow into the thermal energy exchanger 26.

In the thermal energy exchanger 26, the conditioned air flows throughthe air spaces 52 defined by the louvered fins 48 and the tubes 46 ofthe thermal energy exchanger 26. The conditioned air absorbs thermalenergy from the phase change material 56 disposed in the tubes 46. Thetransfer of thermal energy from the phase change material 56 to theconditioned air cools and solidifies the phase change material 56. It isunderstood that the fluid 37 from the source of cooled fluid 30 can alsocirculate through the conduit 38 and the thermal energy exchanger 26, asshown in FIG. 3. The fluid 37 flows from the source of cooled fluid 30through the tubes 46 to absorb thermal energy from the phase changematerial 56 disposed therein. Accordingly, the transfer of thermalenergy to the fluid 37 further cools and solidifies the phase changematerial 56.

When the fuel-powered engine of the vehicle is not in operation, thefluid 37 from the source of cooled fluid 30 does not circulate throughthe conduits 36, 38. Accordingly, the fluid 37 does not circulatethrough the evaporator core 24 or the thermal energy exchanger 26. Theair from the inlet section 16 flows into and through the evaporator core24 where a temperature thereof is unchanged. The air stream then exitsthe evaporator core 24 and is selectively permitted by the blend door 29to flow into the thermal energy exchanger 29.

In the thermal energy exchanger 26, the air flows through the air spaces52 defined by the louvered fins 48 and the tubes 46 of the thermalenergy exchanger 26. The air is cooled to a desired temperature by atransfer of thermal energy from the phase change material 56 disposedtherein to the air. Accordingly, the phase change material 56 is causedto melt. The conditioned cooled air then exits the thermal energyexchanger 26 and flows through the heater core 28, which is not inoperation, and into the outlet and distribution section.

FIG. 6 shows an HVAC system according to another embodiment of theinvention. Reference numerals for similar structure in respect of thedescription of FIGS. 1 thru 5 are repeated in FIGS. 6 thru 8 with aprime (′) symbol. An HVAC system 10′ includes a control module 12′ tocontrol at least a temperature of the passenger compartment. The module12′ illustrated includes a hollow main housing 14′ with an air flowconduit 15′ formed therein. The housing 14′ includes an inlet section16′, a mixing and conditioning section 18′, and an outlet anddistribution section (not shown). In the embodiment shown, an air inlet22′ is formed in the inlet section 16′. The air inlet 22′ is in fluidcommunication with a supply of air (not shown). The supply of air can beprovided from outside of the vehicle, recirculated from the passengercompartment of the vehicle, or a mixture of the two, for example. Theinlet section 16′ is adapted to receive a blower wheel (not shown)therein to cause air to flow through the air inlet 22′. A filter (notshown) can also be provided upstream or downstream of the inlet section16′ if desired.

The mixing and conditioning section 18′ of the housing 14′ is adapted toreceive an evaporator core 24′, and at least one of a heat exchanger 80and a heater core 28′ therein. In the embodiment shown, the heatexchanger 80 and the heater core 28′ are disposed downstream of a blenddoor 29′. The blend door 29′ is adapted to selectively permit a flow ofair through the heat exchanger 80 and the heater core 28′ when the HVACsystem 10′ is not operating in a pull-down mode. A filter (not shown)can be provided upstream of the evaporator core 24′, if desired.

The evaporator core 24′ is in fluid communication with a source ofcooled fluid 30′ such as a refrigeration system, for example, through aconduit 36′. The evaporator core 24′ is adapted to absorb thermal energyand cool the air flowing therethrough when a fuel-powered engine of thevehicle is in operation. The heat exchanger 80 is in fluid communicationwith a thermal energy exchanger 82 through a conduit 84. The conduit 84includes a pump 88 adapted to cause a fluid 90 disposed therein tocirculate. It is understood that the fluid 90 can be any conventionalfluid such as a coolant, for example. The fluid 90 is adapted to absorbthermal energy and cool the air flowing through the heat exchanger 80when a fuel-powered engine of the vehicle is not in operation. Thethermal energy exchanger 82 is also in fluid communication with thesource of cooled fluid 30′ through a conduit 86. The conduit 86 caninclude a valve 87 disposed therein to selectively militate against aflow of the fluid 37′ therethrough. In the embodiment shown, the heatercore 28′ is in fluid communication with a source of heated fluid 74′through a conduit 76′. The source of heated fluid 74′ can be anyconventional source of heated fluid such as the fuel-powered engine ofthe vehicle, for example, and the heated fluid can be any conventionalfluid such as an engine coolant, for example. A valve 75′ can bedisposed in the conduit 76′ to selectively militate against a flow ofheated fluid therethrough. It is understood that the heat exchanger 80can be in fluid communication with the source of heated fluid 74′ asdesired without departing from the scope and spirit of the invention.

In the embodiment shown, the thermal energy exchanger 82 includes a mainhousing 92 having a hollow interior. The main housing 92 may be made ofconventional materials such as polypropylene, for example. In theembodiment shown, the main housing 92 is generally rectangular in shape.It is understood that the main housing 92 can have other shapes asdesired. The main housing 92 includes a first inlet 94, a second inlet96, a first outlet 98, and a second outlet 100 formed thereon. Theinlets 94, 96 and the outlets 98, 100 are formed to extend laterallyoutwardly from the main housing 92. The first inlet 94 and the firstoutlet 98 are in fluid communication with the source of cooled fluid 30′through the conduit 86. The second inlet 96 and the second outlet 100are in fluid communication with the heat exchanger 80 through theconduit 84. The inlets 94, 96 and the outlets 98, 100 each perform as adiffuser to decrease a flow velocity of the respective fluids 37′, 90circulated therethrough. An insulating material 102 can be disposed onan outer surface of the main housing 92 to militate against adissipation of thermal energy therefrom.

The first inlet 94 and the first outlet 98 are fluidly connected by aplurality of tubes 104. The tubes 104 are disposed in the hollowinterior of the thermal energy exchanger 82 and are adapted to receivethe fluid 37′ therethrough. The tubes 104 include a plurality of spacedapart fins 106 extending radially outwardly therefrom. The fins 106enhance a transfer of thermal energy between the fluids 37′, 90. Thetubes 104 and the fins 106 are produced from a thermally conductivematerial such as copper, for example. The tubes 104 are substantiallyparallel in relation to each other and are spaced apart to define aseries of open areas 108 therebetween. The open areas 108 permit a flowof the fluid 90 therethrough.

The fluid 90 includes a phase change material 56′ disposed therein. Thephase change material 56′ is any material that melts and solidifies atcertain temperatures and is capable of storing and releasing thermalenergy such as a paraffin wax, an alcohol, water, and any combinationthereof, for example. As shown in FIGS. 7 and 8, the phase changematerial 56′ is encapsulated in a thermally conductive casing 60 a′, orcoated with a thermally conductive coating 60 b′. The casing 60 a′ andthe coating 60 b′ can be produced from any conventional material such asa polyethylene, for example. The casing 60 a′ and the coating 60 b′permit the phase change material 56′ to be disposed in the fluid 90circulating through the open areas 108. The encapsulated phase changematerial 56′ is adapted to absorb thermal energy of the fluid 90 flowingthrough the heat exchanger 80 when the fuel-powered engine is not inoperation, and release thermal energy into the fluid 37′ when thefuel-powered engine is in operation. As illustrated in FIG. 8, theencapsulated phase change material 56′ can include a thermallyconductive material 58′ disposed therein to further enhance the transferof thermal energy, if desired.

The second inlet 96 and the second outlet 100 are fluidly connected bythe open areas 108. As shown, each of the second inlet 96 and the secondoutlet 100 can include a screen 110 extending across a diameter thereof.The screen 110 is adapted to permit the flow of the fluid 90therethrough, while militating against the flow of the encapsulatedphase change material 56′ from the thermal energy exchanger 82. It isunderstood that the first inlet 94 and the first outlet 98 can befluidly connected by open areas and the second inlet 96 and the secondoutlet 100 fluid connected by tubes, if desired.

In use, when the fuel-powered engine of the vehicle is in operation, thefluid 37′ from the source of cooled fluid 30′ circulates through theconduits 36′, 86. Accordingly, the fluid 37′ circulates through theevaporator core 24′ and the thermal energy exchanger 82. The air fromthe inlet section 16′ flows into the evaporator core 24′ where the airis cooled to a desired temperature by a transfer of thermal energy fromthe air to the fluid 37′ from the source of cooled fluid 30′. Theconditioned air stream then exits the evaporator core 24′. When the HVACsystem 10′ is not operating in the pull-down mode, the air from theevaporator core 24′ is selectively permitted by the blend door 29′ toflow through the heat exchanger 80 and the heater core 28′, which is notin operation, and into the outlet and distribution section. The fluid37′ circulating through the conduit 86 flows into and through the tubes104 of the thermal energy exchanger 82. The fluid 37′ absorbs thermalenergy from the fluid 90 flowing through the open areas 108 and thephase change material 56′ disposed therein. The transfer of thermalenergy cools and solidifies the phase change material 56′.

When the fuel-powered engine of the vehicle is not in operation, thefluid 37′ from the source of cooled fluid 30′ does not circulate throughthe conduits 36′, 86. Accordingly, the fluid 37′ does not circulatethrough the evaporator core 24′ or the thermal energy exchanger 82. Thepump 88 causes the fluid 90 to circulate through the conduit 84, thethermal energy exchanger 82, and the heat exchanger 80. The air from theinlet section 16′ flows into the evaporator core 24′ where a temperaturethereof is unchanged. The air then exits the evaporator core 24′ and isselectively permitted by the blend door 29′ to flow into the heatexchanger 80.

In the heat exchanger 80 the air is cooled to a desired temperature by atransfer of thermal energy from the air to the fluid 90 circulatingtherethrough. The fluid 90 absorbs and transfers the thermal energy fromthe air to the phase change material 56′ disposed therein, causing thephase change material 56′ to melt. The conditioned cooled air then exitsthe heat exchanger 80 and flows through the heater core 28′, which isnot in operation, and into the outlet and distribution section.

FIGS. 9 and 10 show an HVAC system according to another embodiment ofthe invention. Reference numerals for similar structure in respect ofthe description of FIGS. 1 thru 8 are repeated in FIGS. 9 and 10 with aprime (″) symbol. An HVAC system 10″ includes a control module 12″ tocontrol at least a temperature of the passenger compartment. The module12″ illustrated includes a hollow main housing 14″ with an air flowconduit 15″ formed therein. The housing 14″ includes an inlet section16″, a mixing and conditioning section 18″, and an outlet anddistribution section (not shown). In the embodiment shown, an air inlet22″ is formed in the inlet section 16″. The air inlet 22″ is in fluidcommunication with a supply of air (not shown). The supply of air can beprovided from outside of the vehicle, recirculated from the passengercompartment of the vehicle, or a mixture of the two, for example. Theinlet section 16″ is adapted to receive a blower wheel (not shown)therein to cause air to flow through the air inlet 22″. A filter (notshown) can be provided upstream or downstream of the inlet section 16″if desired.

The mixing and conditioning section 18″ of the housing 14″ is adapted toreceive an evaporator core 24″, and at least one of a heat exchanger 80″and a heater core (not shown) therein. In the embodiment shown, the heatexchanger 80″ is disposed downstream of a blend door 29″. The blend door29″ is adapted to selectively permit a flow of air through the heatexchanger 80″ when the HVAC system 10″ is not operating in a pull-downmode. A filter (not shown) can also be provided upstream of theevaporator core 24″, if desired.

The evaporator core 24″ is in fluid communication with a source ofcooled fluid 30″ such as a refrigeration system, for example, through aconduit 36″. The evaporator core 24″ is adapted to absorb thermal energyand cool the air flowing therethrough when a fuel-powered engine of thevehicle is in operation. The heat exchanger 80″ is in fluidcommunication with a thermal energy exchanger 82″ through a conduit 84″.The conduit 84″ includes a pump 88″ and a valve 89 disposed therein. Thepump 88″ is adapted to cause a fluid (not shown) disposed therein tocirculate. The valve 89 selectively militates against a flow of thefluid therethrough. It is understood that the fluid can be anyconventional fluid such as an engine coolant, for example. The fluid isadapted to absorb thermal energy and cool the air flowing through theheat exchanger 80″ when the fuel-powered engine of the vehicle is not inoperation. The thermal energy exchanger 82″ is also in fluidcommunication with the source of cooled fluid 30″ through a conduit 86″.The conduit 86″ can include a valve 87″ disposed therein to selectivelymilitate against a flow of the fluid therethrough. In the embodimentshown, the heat exchanger 80″ is also in fluid communication with asource of heated fluid 74″ through a conduit 76″. The source of heatedfluid 74″ can be any conventional source of heated fluid such as thefuel-powered engine of the vehicle, for example, and the heated fluidcan be any conventional fluid such as an engine coolant, for example. Avalve 75″ may be disposed in the conduit 76″ to selectively militateagainst a flow of heated fluid therethrough. The heat exchanger 80″ isadapted to release thermal energy and heat the air flowing therethroughwhen the fuel-powered engine of the vehicle is in operation. It isunderstood that the source of heated fluid 74″ can be in fluidcommunication with a heater core as desired without departing from thescope and spirit of the invention.

In the embodiment shown, the thermal energy exchanger 82″ includes amain housing 92″ having a hollow interior. The main housing 92″ may bemade of conventional materials such as polypropylene, for example. Inthe embodiment shown, the main housing 92″ is generally rectangular inshape. It is understood that the main housing 92″ can have other shapesas desired. The main housing 92″ includes a first inlet 94″, a secondinlet 96″, a first outlet 98″, and a second outlet 100″ formed thereon.The inlets 94″, 96″ and the outlets 98″, 100″ are formed to extendlaterally outwardly from the main housing 92″. The first inlet 94″ andthe first outlet 98″ are in fluid communication with the source ofcooled fluid 30″ through the conduit 86″. The second inlet 96″ and thesecond outlet 100″ are in fluid communication with the heat exchanger80″ through the conduit 84″. The inlets 94″, 96″ and the outlets 98″,100″ each perform as a diffuser to decrease a flow velocity of thefluids circulated therethrough. An insulating material 102″ can bedisposed on an outer surface of the main housing 92″ to militate againsta dissipation of thermal energy therefrom.

The first inlet 94″ and the first outlet 98″ are fluidly connected by aplurality of tubes 104″. The tubes 104″ are disposed in the hollowinterior of the thermal energy exchanger 82″ and are adapted to receivethe fluid from the source of cooled fluid 30″ therethrough. The tubes104″ include a plurality of spaced apart fins 106″ extending radiallyoutwardly therefrom. The fins 106″ enhance a transfer of thermal energybetween the fluid from the source of cooled fluid 30″ and fluid from theheat exchanger 80′. The tubes 104″ and the fins 106″ are produced from athermally conductive material such as copper, for example. The tubes104″ are substantially parallel in relation to each other and are spacedapart to define a series of open areas 108″ therebetween.

As illustrated in FIG. 9 and 10, the second inlet 96″ and the secondoutlet 100″ can also be fluidly connected by a plurality of tubes 112.The tubes 112 are disposed in the hollow interior of the thermal energyexchanger 82″ and are adapted to receive the fluid from the heatexchanger 80″ therethrough. The tubes 112 include a plurality of spacedapart fins 114 extending radially outwardly therefrom. The fins 114enhance a transfer of thermal energy between the fluids. The tubes 112and the fins 114 are produced from a thermally conductive material suchas copper, for example. The tubes 112 are substantially parallel inrelation to each other and are spaced apart to define a series of openareas 116 therebetween. It is understood that the tubes 112 can beinterleaved with the tubes 104″, as shown in FIG. 10, to further enhancethe transfer of thermal energy between the fluids, if desired. It isfurther understood that the tubes 112 can include a plurality of spacedapart fins (not shown) extending radially inwardly and an encapsulatedphase change material (not shown) disposed therein, if desired, tofurther enhance the transfer of thermal energy.

The open areas 116 formed between the tubes 112 are in fluidcommunication with the open areas 108″ formed between the tubes 104″.The open areas 108″, 116 include a phase change material 56″ disposedtherein. The phase change material 56″ is any material that melts andsolidifies at certain temperatures and is capable of storing andreleasing thermal energy such as a paraffin wax, an alcohol, water, andany combination thereof, for example. In the embodiment shown, the phasechange material 56″ is adapted to absorb thermal energy of the fluidflowing through the tubes 112 when the fuel-powered engine is not inoperation, and release thermal energy to the fluid flowing through thetubes 108″ when the fuel-powered engine is in operation. As illustratedin FIGS. 9 and 10, the phase change material 56″ can include a thermallyconductive material 58″ disposed therein to further enhance the transferof thermal energy. A pocket of air 118 is disposed inside the interiorof the thermal energy exchanger 82″ to permit the phase change material56″ disposed therein to expand when releasing thermal energy to thefluid from the source of cooled fluid 30″.

In use, when the fuel-powered engine of the vehicle is in operation, thefluid from the source of cooled fluid 30″ circulates through theconduits 36″, 86″. Accordingly, the fluid from the source of cooledfluid 30″ circulates through the evaporator core 24″ and the thermalenergy exchanger 82″. The air from the inlet section 16″ flows into theevaporator core 24″ where the air is cooled to a desired temperature bya transfer of thermal energy from the air to the fluid from the sourceof cooled fluid 30″. The conditioned air stream then exits theevaporator core 24″. When the HVAC system 10″ is not operating in thepull-down mode, the air from the evaporator core 24″ is selectivelypermitted by the blend door 29″ to flow through the heat exchanger 80″and into the outlet and distribution section. The fluid circulatingthrough the conduit 86″ flows into and through the tubes 104″ of thethermal energy exchanger 82″. The fluid absorbs thermal energy from thephase change material 56″ disposed in the open areas 108″, 116. Thetransfer of thermal energy cools and solidifies the phase changematerial 56″. Additionally, the phase change material 56″ cools thefluid circulating through conduit 84″ and the heat exchanger 80″ byabsorbing thermal energy therefrom. The thermal energy absorbed by thephase change material 56″ is then transferred to the fluid from thesource of cooled fluid 30″.

When the fuel-powered engine of the vehicle is not in operation, thefluid from the source of cooled fluid 30″ does not circulate through theconduits 36″, 86″. Accordingly, the fluid does not circulate through theevaporator core 24″ or the thermal energy exchanger 82″. The pump 88″causes the fluid disposed in the heat exchanger 80″ to circulate throughthe conduit 84″ and the thermal energy exchanger 82″. The fluid flowsinto and through the tubes 112 of the thermal energy exchanger 82″,releasing thermal energy to the phase change material 56″ disposed inthe open areas 108″, 116 thereof. Accordingly, the fluid is cooled bythe phase change material 56″. The air from the inlet section 16″ flowsinto and through the evaporator core 24″ where a temperature thereof isunchanged. The air then exits the evaporator core 24″ and is selectivelypermitted to flow through the heat exchanger 80″.

In the heat exchanger 80″, the air is cooled to a desired temperature bya transfer of thermal energy from the air to the fluid circulatingtherethrough. The fluid absorbs and transfers the thermal energy fromthe air to the phase change material 56″ disposed in the open areas108″, 116 of the thermal energy exchanger 82″ Thus, the phase changematerial 56″ is caused to melt. The conditioned cooled air then exitsthe heat exchanger 80″ and flows into the outlet and distributionsection.

FIG. 11 shows an HVAC system according to another embodiment of theinvention. Reference numerals for similar structure in respect of thedescription of FIGS. 1 thru 10 are repeated in FIG. 11 with a prime (′″)symbol. An HVAC system 10′″ includes a control module 12′″ to control atleast a temperature of the passenger compartment. The module 12′″illustrated includes a hollow main housing 14′″ with an air flow conduit15′″ formed therein. The housing 14′″ includes an inlet section 16′″, amixing and conditioning section 18′″, and an outlet and distributionsection (not shown). In the embodiment shown, an air inlet 22′″ isformed in the inlet section 16′″. The air inlet 22′″ is in fluidcommunication with a supply of air (not shown). The supply of air can beprovided from outside of the vehicle, recirculated from the passengercompartment of the vehicle, or a mixture of the two, for example. Theinlet section 16′″ is adapted to receive a blower wheel (not shown)therein to cause air to flow through the air inlet 22′″ A filter (notshown) can be provided upstream or downstream of the inlet section 16′″if desired.

The mixing and conditioning section 18′″ of the housing 14′″ is adaptedto receive an evaporator core 24′″, a heat exchanger 80′″, and a heatercore 28′″ therein. In the embodiment shown, the heat exchanger 80′″ andthe heater core 28′″ are disposed downstream of a blend door 29′″. Theblend door 29′″ is adapted to selectively permit a flow of air throughthe heat exchanger 80′″ and the heater core 28′″ when the HVAC system10′″ is not operating in a pull-down mode. A filter (not shown) can beprovided upstream of the evaporator core 24′″, if desired. Theevaporator core 24′″ is in fluid communication with a source of cooledfluid 30′″ such as a refrigeration system, for example, through aconduit 36′″. The evaporator core 24′″ is adapted to absorb thermalenergy and cool the air flowing therethrough when a fuel-powered engineof the vehicle is in operation. The heat exchanger 80′″ is in fluidcommunication with a thermal energy exchanger 120 through a conduit84′″. The conduit 84′″ includes a pump 88′″ adapted to cause a fluid90′″ disposed therein to circulate. It is understood that the fluid 90′″can be any conventional fluid such as a coolant, for example. The fluid90″ is adapted to absorb thermal energy and cool the air flowing throughthe heat exchanger 80′″ when the fuel-powered engine of the vehicle isnot in operation. In the embodiment shown, the heater core 28′″ is influid communication with a source of heated fluid 74′″ through a conduit76′″. The source of heated fluid 74′″ can be any conventional source ofheated fluid such as the fuel-powered engine of the vehicle, forexample, and the heated fluid can be any conventional fluid such as anengine coolant, for example. A valve 75′″ may be disposed in the conduit76″ to selectively militate against a flow of heated fluid therethrough.It is understood that the heat exchanger 80′″ can be in fluidcommunication with the source of heated fluid 74′″ as desired withoutdeparting from the scope and spirit of the invention.

In the embodiment shown, the thermal energy exchanger 120 includes amain housing 122 having a hollow interior. The main housing 122 may bemade of conventional materials such as polypropylene, for example. Inthe embodiment shown, the main housing 122 is generally rectangular inshape. It is understood that the main housing 122 can have other shapesas desired. The main housing 122 includes a first aperture 124 and asecond aperture 126. The apertures 124, 126 are adapted to receive aninlet end 128 and an outlet end 130 of the conduit 84′″ therethrough.The inlet end 128 and the outlet end 130 extend through the respectiveapertures 124, 126 and into the fluid 90′″.

The fluid 90′″ includes a phase change material 56′″ disposed therein.The phase change material 56′″ is any material that melts and solidifiesat certain temperatures and is capable of storing and releasing thermalenergy such as a paraffin wax, an alcohol, water, and any combinationthereof, for example. As shown in FIGS. 12 and 13, the phase changematerial 56′″ is encapsulated in a thermally conductive casing 60 a′″,or coated with a thermally conductive coating 60 b′″. The casing 60 a′″and the coating 60 b′″ can be produced from any conventional materialsuch as a polyethylene, for example. The casing 60 a′″ and the coating60 b′″ permit the phase change material 56′″ to be disposed in the fluid90 circulating through the conduit 84′″ and the heat exchanger 80′″. Theencapsulated phase change material 56′″ is adapted to absorb thermalenergy of the fluid 90′″ flowing through the heat exchanger 80′″ whenthe fuel-powered engine is not in operation. As illustrated in FIG. 13,the encapsulated phase change material 56′″ can include a thermallyconductive material 58′″ disposed therein to further enhance thetransfer of thermal energy if desired. It is understood that the inletend 128 and the outlet end 130 of the conduit 84′″ can include a screenadapted to permit the flow of the fluid 90′″ therethrough, whilemilitating against the flow of the encapsulated phase change material56′″ from the thermal energy exchanger 120, if desired.

In use, when the fuel-powered engine of the vehicle is in operation, thefluid from the source of cooled fluid 30′″ circulates through theconduit 36′″. Accordingly, the fluid circulates through the evaporatorcore 24′″. The air from the inlet section 16′″ flows into the evaporatorcore 24′″ where the air is cooled to a desired temperature by a transferof thermal energy from the air to the fluid from the source of cooledfluid 30′″. The conditioned air stream then exits the evaporator core24′″. When the HVAC system 10′″ is not operating in the pull-down mode,the air from the evaporator core 24′″ is selectively permitted by theblend door 29′″ to flow into and through the heat exchanger 80′″. In theheat exchanger 80′″, the conditioned air absorbs thermal energy from thefluid 90′″ circulating therein. The transfer of thermal energy from thefluid 90′″ cools the fluid 90′″. Accordingly, the fluid 90′″ absorbsthermal energy from the phase change material 56′″ disposed therein. Thetransfer of thermal energy from the phase change material 56′″ to thefluid 90′″ cools and solidifies the phase change material 56′″. Theconditioned air stream then flows through the heater core 28′″, which isnot in operation, and into the outlet and distribution section.

When the fuel-powered engine of the vehicle is not in operation, thefluid from the source of cooled fluid 30′″ does not circulate throughthe conduit 36′″. Accordingly, the fluid does not circulate through theevaporator core 24′″. The air from the inlet section 16′″ flows into andthrough the evaporator core 24′″ where a temperature thereof isunchanged. The air then exits the evaporator core 24′″ and isselectively permitted by the blend door 29′″ to flow into the heatexchanger 80′″.

In the heat exchanger 80′″ the air is cooled to a desired temperature bya transfer of thermal energy from the air to the fluid 90′″ circulatingtherethrough. The pump 88′″ causes the fluid 90′″ to circulate throughthe conduit 84′″ and the thermal energy exchanger 120. The fluid 90′″absorbs and transfers the thermal energy from the air to the phasechange material 56′″ disposed therein. Thus, the phase change material56′″ is caused to melt. The conditioned cooled air then exits the heatexchanger 80′″ and flows through the heater core 28′″, which is not inoperation, and into the outlet and distribution section.

From the foregoing description, one ordinarily skilled in the art caneasily ascertain the essential characteristics of this invention and,without departing from the spirit and scope thereof, can make variouschanges and modifications to the invention to adapt it to various usagesand conditions.

1. A thermal energy exchanger for a heating, ventilating, and airconditioning system comprising: a main housing having a hollow interior;a plurality of tubes disposed in the hollow interior of the housing; anda phase change material disposed in the tubes, wherein the phase changematerial is at least one of encapsulated with a thermally conductivematerial and impregnated with a thermally conductive material.
 2. Thethermal energy exchanger according to claim 1, wherein the tubes includea plurality of internal fins.
 3. The thermal energy exchanger accordingto claim 1, wherein the tubes include at least one screen adapted tomilitate against a flow of the phase change material therefrom.
 4. Thethermal energy exchanger according to claim 1, wherein the tubes are influid communication with a source of cooled fluid.
 5. The thermal energyexchanger according to claim 4, wherein the phase change material iscooled and solidified by at least one of a fluid from the source ofcooled fluid and a flow of air therethrough.
 6. A thermal energyexchanger for a heating, ventilating, and air conditioning systemcomprising: a hollow main housing including a first inlet and a firstoutlet, wherein the first inlet and the first outlet are in fluidcommunication with a source of cooled fluid, the housing furtherincluding a second inlet and a second outlet, wherein the second inletand the second outlet are in fluid communication with a heat exchangerdisposed in a control module of a heating, ventilating, and airconditioning system, and wherein each of the inlets and the outletsperform as a diffuser; a plurality of tubes disposed in the housingforming open areas therebetween, wherein at least one of the tubes isadapted to receive one of a fluid from the source of cooled fluid and afluid from the heat exchanger therethrough; and a phase change materialdisposed in the open areas of the housing.
 7. The thermal energyexchanger according to claim 6, wherein the phase change material is atleast one of encapsulated with a thermally conductive material andimpregnated with a thermally conductive material.
 8. The thermal energyexchanger according to claim 6, wherein the phase change material iscooled and solidified by a fluid from the source of cooled fluid.
 9. Thethermal energy exchanger according to claim 6, wherein the phase changematerial is disposed in one of the fluid from the source of cooled fluidand the fluid from the heat exchanger.
 10. The thermal energy exchangeraccording to claim 6, wherein at least one of the inlets and the outletsincludes a screen to militate against a flow of the phase changematerial therefrom.
 11. The thermal energy exchanger according to claim6, wherein the tubes include radially outwardly extending fins formedthereon.
 12. The thermal energy exchanger according to claim 6, whereinthe tubes include radially inwardly extending fins formed thereon. 13.The thermal energy exchanger according to claim 6, wherein one of thetubes fluidly connects the first inlet and the first outlet.
 14. Thethermal energy exchanger according to claim 6, wherein one of the tubesfluidly connects the first inlet and the first outlet.
 15. The thermalenergy exchanger according to claim 6, wherein one of the tubes fluidlyconnects the second inlet and the second outlet.
 16. The thermal energyexchanger according to claim 6, wherein the tubes are interleaved.
 17. Athermal energy exchanger for a heating, ventilating, and airconditioning system comprising: a main housing having a hollow interior;a fluid disposed in the housing, the fluid adapted to circulate througha conduit to a heat exchanger disposed in an HVAC module of a heating,ventilating, and air conditioning system; and a phase change materialdisposed in the fluid, wherein the phase change material is at least oneof encapsulated with a thermally conductive material and impregnatedwith a thermally conductive material.
 18. The thermal energy exchangeraccording to claim 17, wherein the conduit includes an inlet end and anoutlet end disposed in the housing.
 19. The thermal energy exchangeraccording to claim 17, wherein each of the inlet end and the outlet endof the conduit includes a screen disposed therein to militate against aflow of the phase change material from the housing.
 20. The thermalenergy exchanger according to claim 17, wherein the phase changematerial is cooled and solidified by at least one of the fluid and aflow of air through the heat exchanger.